Molecular identification and antifungal susceptibility of 186 Candida isolates from vulvovaginal candidiasis in southern China

Abstract

There is limited information regarding the molecular epidemiology and antifungal susceptibilities of Candida isolates using the Neo-Sensitabs method in patients with vulvovaginal candidiasis (VVC). From August 2012 to March 2013, 301 non-pregnant patients aged 18-50 years with suspected VVC were prospectively screened at a teaching hospital in southern China. The vaginal isolates were identified by DNA sequencing of internal transcribed spacer and the D1/D2 domain. Antifungal susceptibility testing of seven antifungal agents was performed using the NeoSensitabs tablet diffusion method. Candida species were isolated from 186 cases (61.79 %). The most common pathogen was Candida albicans (91.4 %), followed by Candida glabrata (4.3 %), Candida tropicalis (3.2 %) and Candida parapsilosis (1.1 %). The susceptibility rates to C. albicans were higher for caspofungin, voriconazole and fluconazole than those for itraconazole, miconazole, ketoconazole and terbinafine (P,0.01). The resistance rates to C. albicans were 4.7, 6.5, 7.1, 7.6, 12.3, 27.7 and 74.7 % for caspofungin, miconazole, itraconazole, voriconazole, fluconazole, ketoconazole and terbinafine, respectively. No drugs tested apart from fluconazole exhibited differences in resistance between C. albicans and non-albicans Candida isolates. The results demonstrate that, using DNA sequencing, C. albicans is the most common isolate from Chinese patients with VVC. Caspofungin, voriconazole and fluconazole may be preferable to other azoles and terbinafine in the treatment of VVC.

Comparative Analysis of the Capacity of the Candida Species To Elicit Vaginal Immunopathology

“…Moreover, C. dubliniensis is almost indistinguishable from C. albicans using this methodology, possibly leading to low reported rates of C. dubliniensis as an etiological agent of VVC (35). That said, molecular diagnostics (e.g., PCR) to distinguish Candida species largely report findings similar to those of culture-based identification (12,24,36). Thus, imperfect or infrequently used diagnostic tools, selfdiagnosis, and availability of over-the-counter treatment options may contribute to the potentially underreported rate of NAC vaginitis.…”

“…In support of this, a clinical study by Dennerstein et al demonstrated that of 44 women presenting with vaginitis-like symptoms and harboring a NAC yeast, 86% reported spontaneous improvement without requiring antifungal intervention (30). On the other hand, the relatively large number (ϳ5% to 10%) of VVC cases universally caused by C. glabrata cannot be denied, suggesting that NAC species do actively contribute to symptomatic VVC (20,23,24,28). C. glabrata remains a formidable clinical challenge, as these infections are largely unresponsive to standard fluconazole therapy, given the intrinsic resistance of C. glabrata to the azole class (54).…”

“…While the majority (ϳ90%) of VVC cases are due to infection with C. albicans (1), other, non-albicans Candida (NAC) species have been implicated as causative agents of VVC, and their incidence is disproportionately high in certain geographic regions (11). Retrospective reports indicate that identification of NAC species during VVC episodes range anywhere from 5% to 50% of total Candida species isolated (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Of these, C. glabrata is most frequently reported as the second leading causative agent (ϳ5%), and the remainder are most commonly composed of C. krusei, C. parapsilosis, and C. tropicalis (11,20,23).…”

<p>Antifungal Activity of ZnO Nanoparticles and Nystatin and Downregulation of SAP1-3 Genes Expression in Fluconazole-Resistant <em>Candida albicans</em> Isolates from Vulvovaginal Candidiasis</p>

“…6,10 Among the Fluconazole-resistant isolates, mutations in the ERG11 gene among the candida species are responsible for significant differences in their susceptibility to Fluconazole. 11 Secreted Aspartyl Proteinases (SAP) are considered as a potential factor that may affect the virulence of this yeast. Extracellular proteolytic activity of candida species is caused by SAP.…”

A prospective study to compare the efficacy and safety of tioconazole and clotrimazole vaginal gel in patients suffering from vulvovaginal candidiasis

“…7,8 The reported drug resistance to use of clotrimazole is low and while clotrimazole has been the standard treatment offered, newer medication may also be also as effective. 9 Tioconazole being a single dose application administered by the treating doctor not only ensures complete compliance but also is reassuring to the patient and this probably enhances patient acceptability greatly. In addition it has also been reported that gel form provides for a longer contact time of the active component at the desired location, and results in a more efficient use of the active component and improved effectiveness Gel formulations generally provide faster drug release as compared to ointments and creams and may be useful when available.…”